Dengue and other arboviral infections: Case

This boy has dengue with warning signs progressing to the plasma-leak critical phase. His travel to the Philippines without bite avoidance, the defervescence of his fever with new abdominal pain, vomiting and lethargy, the positive NS1 antigen, the 23 per cent rise in haematocrit over baseline, and the thrombocytopenia together meet WHO 2009 criteria for dengue with warning signs, and his narrowed pulse pressure of 26 mmHg with cool peripheries places him at the threshold of compensated shock. The clinical task over the next 24 to 48 hours is to escort him safely through the leak with titrated isotonic crystalloid. ^[2]

Clinical findings

The key findings are the warning signs (abdominal pain, persistent vomiting, lethargy), the haematocrit-platelet signature of leak (a haematocrit of 0.48 against a baseline of 0.39, platelets 58 x10^9/L), the mild hypoalbuminaemia of capillary leak, and the borderline perfusion with a narrowed pulse pressure. He is not yet in severe dengue by the strict criterion (pulse pressure remains above 20 mmHg and there is no organ impairment), but he sits at the boundary, so close monitoring and a clear escalation plan are essential. ^[1]

The candidate should articulate the problem representation clearly: a school-age returned traveller with dengue, defervescence, warning signs and a rising haematocrit, in WHO group B at risk of progression to severe dengue. This single statement tells examiner diagnosis, the classification, the severity and the plan. ^[3]